Fluid pump



Dec. A12, 1950 L. H. scHMoHL. ETAL 2,533965 Y FLUID PUMP Filed Deo. 24.1945 d /a .32 1 s 6/7 47 2l B V Q46 I/ d4] f 2226 A 59 49 "-75 iff-43 F'Z 38 36 y mf 40 i 35 J/ /85 Z l A (lill/ Patented Dec. 12, 1950 UNITEDSTATES PATENT FF ICE FLUID PUMP corporation of Ohio Application December24, 1946, Serial No. 718,146

l Claim.

This invention relates to new and useful improvements in fluid pumps andis more particularly directed to piston pumps of the types used inaircraft for priming the engines with explosive fluid and for pumpingdeicing fluid to windshields.

In piston type pumps it is customary to provide two valves forcontrolling the .passage of port.

In the present invention it is an object to provide a ,piston type pumpin which a single valve Ielement is associated with both the inlet andoutlet ports for controlling the passage of fluid to and from the pump.

Another object of the invention is to provide a pump of the typedescribed in which a single flexible `valve element serves to normallyclose both the inlet and outlet passages `and which may be flexed bypressure differentials on. the

opposite sides thereof in a manner for opening the inlet and outletports alternately.

Another object of the invention is to provide 'a piston type pump with asingle exible valve element for controlling the inlet and outletpassages in which means is provided for prevent-- ing the valve elementfrom being jammed into the inlet passage by pressure of the dischargingfluid.

Other objects and advantageous features -will become apparent from thefollowing detailed description of a preferred embodiment of theinvention and with reference to the accompanying drawings, in which:

Fig. l is a vertical sectional viewshowing the pump in the normalnon-operating position with the valve disk closing both the inlet andoutlet ports.

Fig. 2 is a fragmentary section showing `the position of the valve diskduring the intake `or suction stroke of the pump piston.

Fig, 3 is a fragmentary section showing the position of the valve diskduring the discharge stroke of the pump piston.

Fig. 4 is a section view taken along line A-A oi' Fig. 2 illustratingthe porting adjacent the inlet valve seat.

Fig. 5 is a section View taken along line B-B of Fig. 1 showing thearrangement vfor locking the piston against withdrawal when the pump isnot in use.

The priming pump embodying the present invention includes a pumpcylinder I in which a piston 2 is mounted for reciprocation. A valvehousing 3 has a circular extension I3 tting within and brazed to thelower end of the cylinder. Obviously the valve housing maybe attached tothe pump cylinder by screw threads or other suitable means, or it may beformed integrally therewith.

The valve housing 3 has abore 4 which lserves as a valve chamber andwhich is threaded toward its outer endas at 5 for receiving a threadedinlet adapter '5. A short counterbore 1 Vis `adapted to receive asealing gasket 8 and a transverse shoulder 9 on the inlet adapter 6abuts the outer face lll of the valve housing for limiting the amountthe adapter may enter the housing.

The inlet adapter 6 has Va bore l! and a threaded means l2 forattachment to a source of fluid supply. A suitable strainer screen 59 ispress fitted within the bore Il and further held in place by the splitring I4. At its inner end the adapter has a ilat, annular inlet valveseat l5 surrounding a shallow, circular recess I which terminates in atransverse wall portion l1. The inlet valve seat l5 is slightly concave.sloping `toward the recess lli. `Several flow passages I8, spacedradially from the center of the recess i6, connect the latter with thebore Il.

The valve housing 3 has a discharge port I9 with a threaded means 20 forattachment to a receiver of the discharged fluid. A central passage 2!connects the discharge port with the valve chamber vl. An annular valveseat 22 surrounds the passage 2i and a frusto-conical face 23 leads tothe peripheral wall of valve chamber t. A passage 2t connects the valvechamber 4 to a pump chamber 25 within the cylinder.

A circular valve disk 25 is interposed between the inlet and outletvalve seats It' and '22. The valve dish is `formed of rubber or othersuitable rubber-like material that is iiexible and preferably flat whenunrestrained. The two valve seats are so dimensioned and spaced withrespect to each other and to the valve disk that normally the latterwill be slightly deformed from `its unrestrained shape and make sealingcontact with both valve seats. Thus, as illustrated in Yclosing oi bothinlet and outlet ports.

3 Figure 1, the inlet valve seat l5 causes the valve disk to bend aslight amount over the outlet valve seat 22, thus insuring initialsealing contact with both Valve seats when the pump is not in operationand also when the fluid pressure within the pump is the same as in theinlet port, as hereinafter more fully explained.

It will be noted that the inlet valve seat I5V is slightly concave andcontacts the valve disk only along the marginal portion thereof. Theoutlet valve seat 22 is cut back as at 23 so that it will contact onlythe central portion of the valve disk along a circle of less diameterthan the smallest circleI of contact between the inlet valve seat andthe valve disk. When the fluid pressure is the same in both the valvechamber and the inlet port, the valve disk is in pressure balance andwill assume the position of Fig. l, When the fluid pressure within thepump is lower than the fluid pressure within the inlet port, the centralportion of the valve disk will be seated tightly against Athe outletvalve seat and the marginal portion will be flexed away from the inletseat and allow the fluid to enter the pump. See Fig. 2. When the fluidpressure within the pump is greater than that within the inlet port, thecentral portion of the valve disk is flexed toward the inlet seat andaway from the outlet valve seat 22, as shown in Fig. 3, thus allowingthe I uid to pass from the pump.

The piston 2 has at its inner end a threaded bore 2l for receiving aguide plug 25. rlhe piston has sufficient clearance 2e to insure that itwill remain out of contact with the bore of the y cylinder I. The guideplug 28 has a head thereon which engages the inner surface of the pumpcylinder and guides the piston. Said plug is made of a material havingsuitable bearing qualities with respect to the material for thecylinthereto by a pin 33 which extends radially beyond the piston as at34. An exteriorly threaded sleeve 35 is attached to the cylinder l bybrazing or other suitable means, and has a counter-bore 36 for receivingsuitable packing rings 3?, 38 and 39. A retaining washer 4l? preventsextrusion of the packings into the clearl ance 29 and also serves as astop engageable by the guide plug 223 for preventing the completewithdrawal of the piston. A packing gland 4i is engaged by the clampingshoulder 42 of the internally threaded packing cap 43 for adjusting thecompression on the packing when the packing cap is threaded onto thesleeve 35. A locknut 44 is threadably mounted on the sleeve for clampingthe priming pump to a suitable mounting bracket 45.

The packing cap 43 has a transverse wall portion 46 spaced from theclamping shoulder 42 and is slotted as at 47. The piston assembly may berotated with respect to the cap 43 and when the pin extension 34 isaligned with one of the slots 47 the piston may be withdrawn forreciprocation.

A ring 48 of rubber or rubber-like material is interposed between thepacking gland 4l and the transverse wall 46. The longitudinal distancebetween the Wall 4B and the packing gland is somewhat less than the sumof the cross sectional diameters of the rubber-like ring 48 and the pin33. When the pin extension 34 is entered through a slot 4l it willstrike the rubberlike ring and the latter must be depressed slightly asat 49 before the pin extension will clear the slot. When the slot hasbeen cleared, the pist0n may be rotated so that the pin extension willbe out of register therewith and thus prevent withdrawal of the piston.The rubber-like ring 48 remains depressed as at 4S to yieldingly pressthe pin extension against the wall 455 and thus provide a frictionallock to prevent accidental rotation and Withdrawal of the piston.

To operate the priming pump, the handle is rotated until the pinextension 34 is in register with a slot 4l and the piston is thenwithdrawn. At the beginning of the piston stroke, the fluid pressureswithin the valve chamber 4 and the inlet port are substantially equaland the valve disk normally closes both the inlet and outlet ports asshown in Fig. l. As the piston is withdrawn, a suction is created withinthe pump which reduces the pressure of the fluid within the valvechamber d below that of the fluid within the inlet port. The resultingpressure differential created on the opposite sides of the valve diskcauses it to flex away'from the inlet valve seat as shown in Fig. 2,allowing fluid to be drawn into the pump. At the end of the outwardstroke the pressures within the valve chamber and inlet' ports aremomentarily equalized and the valve disk resumes its normal position forclosing olf both inlet and outlet ports. On the return stroke of thepiston a pressure is created upon the fluid within the valve chamber 4which is higher than that in the inlet port, causing the marginalportion of the valve disk to seat more tightly against the inlet valveface and forcing the central portion to flex away from the outlet valveseat 22 as shown in Fig. 3, and allowing the fluid to be discharged fromthe pump chamber to the outlet port 2l.

During the discharge stroke, the perforated transverse wall Il serves asa stop to prevent pressure of the discharging fluid from forcing orjamming the valve disk into theinlet passage. Upon completion of thedischarge stroke the pressure within the valve chamber and inlet portsare again equalized and the valve disk returns toits normal position asshown in Fig. l, to complete a pumping cycle. Y

From the above description it is apparent that a priming pump has beenprovided which is simple in operation and construction and which has butone Valve element for controlling both the intake and discharge ports.The valve disk is flexible and is responsive to differentials ofpressure for opening and closing the intake and discharge ports. Whenthe pressure within the valve chamber is substantially the same as inthe intake and discharge ports, the valve disk assumes a position forclosing both ports. When the pressure within the valve chamber becomeslower than that in the intake port, the resulting pressure differentialcauses the disk to flex into a position for opening the inlet. When thepressure within the valve chamber becomes greater Vthan that in theintake port, the valve disk fromV blowing through or becoming jammed inthe intake port.

Although but one embodiment of the invention has been shown anddescribed, it is obvious that many changes may be made in the detailconstruction without departing from the spirit of the invention asdeiined in the following claim.

We claim:

In a uid dispensing device, a pump cylinder, a piston mounted forreciprocation in said pump cylinder, a iiuid chamber in said pumpcylinder, a valve casing connected to said pump cylinder and having aport leading from said fluid chambei' in the pump cylinder to a fluidchamber in said valve casing, said Valve casing having an outlet port, avalve seat surrounding said port, an adapter threaded into said valvecasing, said adapter having an annular valve seat on the inner endthereof, and a transverse wall portion and inlet ports therein disposedradially inwardly of the annular valve seat, a single iiexible valveelement of substantially uniform thickness disposed between the valveseat surrounding the outlet port and the annular valve seat on theadapter and means for limiting the extent to which the adapter may bethreaded into the valve casing whereby the valve seat on the casing andthe valve seat on the adapter initially s Contact with the ilexiblevalve element and flex the same, said valve casing having a recessopposed to the annular valve seat on the adapter whereby said valveelement may be iiexed away Y from the valve seat on the adapter to alimited extent to permit fluid to be drawn into the fluid chamber of thepump and said adapter having a recess in the end thereof directlyopposed 'to the valve seat on the valve casing into which the centralportion of the valve element may be flexed to a limited extent to permitthe ejection of the fluid from the uid chamber of a valve casing throughsaid outlet port.

LELAND H. SCHMOHL.

JOHN L. HABE.

REFERENCES CITED The following references are oi record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 947,536 Wenkel Jan. 25, 19101,506,012 Lewis Aug. 216, 1924 1,633,772 Clapp June 2,8, 1927 2,179,354Scott Nov. 7, 1939

